Method of imparting antistatic properties to textile materials



METHOD on IMPAtt'ElNG ANTISTATIC ratta- ERrtEs To 'rnx'rtan MATERIALS Osborne C. Bacon, Penns Grove, N. 3., and Lehman E. Hughes, New Castle, DeL, assignors to E. 1'. tin Pont de Nemours & Company, Wiimingten, 3.21., a cotporatien of Delaware No Drawing. Application February 27, 1953,

Serial No. 339,432

5. Claims. ((15. Ins-75) is objectionable during the manufacture of the textile and in the finished garment. During the manufacture, the static charge on the fibers or fabric interferes with their convenient handling during spinning, reeling, weaving and the like. Finished articles which are designed to drape like cotton and wool articles fail to do so properly due totheir electrostatic charge and often cling uncomfortably to the wearer.

Many anti-static agents have been proposed to overcome this difficulty of synthetic textiles, however, none is entirely satisfactory either because of effectiveness or the .difficulty of application to the textile material.

It is therefore an object of this invention to provide a novel and effective method for appyling anti-static com- Positions which remain after repeated washings and dry cleanings. Another object is the provision of an antistatic agent which may be applied to synthetic textile fibers and fabrics by padding and exhausting procedures. Other objects will appear as the description of the invention proceeds.

These and other objects are accomplished by the application to textiles of a polyacrylyloxyalkyltrialkyl ammonium alkyl sulfate salt in which the alkyl radicals contain from 1 to 4 carbon atoms, together with up to an equivalent weight of water-soluble salt of a carboxylate or alkyl sulfate having from 8 to 20 carbon atoms. The invention also includes textile materials having anti-static properties produced by these methods. The textiles after treatment carry a small but effective amount of a composition, the active anti-static ingredient of which has the following formula:

' where R is H, CH3 or C2H5; R1 is a divalent hydrocarbon radical of 1 to 4 carbon atoms; R2, R3 and R4 are aliphatic hydrocarbon groups of 1 to 3 carbon atoms; X is a hydrocarbon sulfate or carboxylate anion of 8 to 20 carbon atoms; and n is greater than 10.

The amount usually is about 0.05% to 2.0% or more in extreme cases of the methylsulfate salt or its equivalent based on the weight of the dry textile. The preferred amount is about 0.25% to about 1.0%, and about twice .this amount for the long-chain alkyl sulfate or carboxylate United States Patent 2,729,577 Patented Jan. 3, 1956 methyldiethyl ammonium methylsulfate together with sodium hexadecenyl sulfate yields exceptionally satisfactory hand, color and freedom from odor.

The quaternary salts may be made by any known method. One such method consists essentially of quaternizing an appropriate acrylyloxyalkyldialkylamine in water with dimethyl sulfate followed by polymerization as described in Example II of copending application Serial No. 260,119, filed December 5, 1951.

The water-soluble salts of the alkyl sulfates having from 8 to 20 carbon atoms mentioned above are readily obtainable on the open market where they are sold as detergents. The more common ones are the sodium and amine salts of the alkyl sulfates bearing primary straight-chain alkyl groups. The common amines used are diethanolamine, triethanolamine, and N-diethylcyclohexylamine. The sodium salts of the long-chain alkyl sulfates are preferred in this invention on account of their ready availability and lower cost.

The anti-static composition is diluted to about 0.01% to 0.1% to form an aqueous solution of one of the above defined quaternary salts. The textile material is then placed in the bath, followed by slow addition of the sulfate or carboxylate salt which serves as an exhaustion aid. Alternatively, the salt can be added before the textile. For best operaion, a non-ionic dispersing agent should also be present. The preferred amount of the exhaustion aid is equal to that of the anti-static agent on an equivalent weight basis.

The ratio of the bath to the textile may vary from 10 to 50 parts by weight of the bath for each part of the textile material. Usually more concentrated baths are not satisfactory, although there is no limit to the amount of dilution, except that baths which are more dilute than to 1 may be uneconomical because of inconveniently long application times or limitations on the amount of textile treated per batch.

The temperature of the application bath can vary be tween room temperature and 190 F. Under some conditions the bath may be maintained at its boiling point, but this is usually undesirable for mill use.

This exhaustion procedure may be used on textiles bearing any of the ordinary crease-resistant resin finishes for textiles as will be apparent from certain of the following examples. Among the resins used for this purpose are the methylol ureas, methylol melamines, 1,3bis(hydroxymethyl)-irnidazoiidone and their ethers. These agents impart stiffness, crease-resistance, dimensional stability and other properties to textiles. It is preferable to conduct this process after resin treatment rather than before. Simultaneous application cannot be accomplished.

It has been found that ordinary loadings of these resins and finishes usually increase the static properties of textiles, and therefore the present invention is particularly applicable to textiles treated with these resins together with the compositions of the present invention.

The following examples are given by way of illustration, but it is to be understood that any of the quaternary ammonium compounds and Water-soluble, long-chain sulfates falling within the above generic description of the invention may be substituted in like amount for any of those given in the examples with comparable results.

The treated textiles are tested as described in our copending application Serial No. 260,119.

Example I A. Polyethylene terephthalate stockings are placed in 20 parts by weight of an aqueous solution containing 0.5 weight percent (based on fabric weight) of poly-betamethacrylyloxyethyldiethylmethyl ammonium methylsulfate in water at to F. Then about 100 parts Example II -Example II is repeated using sodium stearate in place of sodium hexadecenyl sulfate. The stockings are found to have a very good anti-static rating. Likewise, very good results are obtained by adding all of the sodium stearate to the bath before the stockings, followed by working the stockings in the bath for 0.5 hour.

Example 111 When Example I is repeated using 0.2, 0.4, 0.6 and 1.0 weight percent of the anti-static agent (based on the weight of hosiery), similar good results are obtained.

Example IV When Example I is repeated with bath to fabricate ratios of :1 and 50:1, the anti-static properties of the stockings are greatly'improved over untreated stockings.

Similar results are obtained when these applications are made at 75 to 100 F. and at 120 to 140 F.

Example V Sweaters made 'of nylon, of cellulose acetate and of polyethylene terephthalate are treated by the procedure of Example I. The resulting anti-static ratings of the sweaters are greatly improved over those of untreated sweaters.

Example VI Textiles made of nylon, polyacrylonitrile, polyethylene terephthalate and of cellulose and cellulose acetate are padded at 100% wet pick-up with an aqueous pad bath containing weight percent (based on the bath) of a commercial dimethylolurea (an aqueous solution containing about monomeric and 4% partially condensed dimethylolurea) and 0.5 Weight percent of a commercial ammonium phosphate catalyst. The fabric is air-dried, baked .3 minutes at 350 F., soaped in a-0.25% tallow soap solution at 120 F. for 15 minutes, rinsed and dried. The resulting fabrics have very poor anti-static properties, which are greatly improved by treatment according to Example I. I

The above padding operation was repeated with a methylated methylol melamine and a commercial (NH4)2HPO4 catalyst, followed by the exhaustion step of Example I. In this case, anti-static ratings were very good and fair for the one bearing the: anti-static agent,

and poor and nil for the piece of fabric bearing only the resin.

This padding operation was repeated again with 15 weight'percent of 1,3-bis (hydroxymethyl)imidazolidone, 0.5 weight percent tartaric acid and 15 weight percent of the same polymeric quaternary ammonium anti-static agent, the latter 'by the exhaustion step of Example I. This treated textile had anti-static ratings of very good and good at 45% and relative humidities. Without the anti-static agent the corresponding values varied from fair to nil. In every case, both with and without the anti-static agent, the pieces of textile have a pleasing hand and satisfactory degrees of crease-resistance and dimensional stability.

The present invention is particularly effective in reducing the anti-static properties of textile materials including fibers, yarns, threads and fabrics prepared from synthetic materials having high electrical resistance, such as those prepared from cellulose acetate, nylon, polyacrylonitrile, and polyethylene terephthalate. Another advantage of the present invention is that the anti-static agents may be applied with resinous, crease-resistant materials which normally increase the static effects of the synthetic polymeric textiles so treated, but when these resins are applied with the compositions of the present invention the static effects of the resin are obviated.

It will be apparent thatmany widely different embodiments of this invention may be made without departing from the spirit and scope thereof, and therefore it is not intended to be limited except as indicated in the appended claims.

We claim:

1. In the method of imparting durable, anti-static properties to textile material which normally accumulate an electrostatic charge the improvement which comprises immersing the textile material in an aqueous solution containing as an anti-static agent (1.) from 0.01% to 0.1% by weight of a polyacrylyloxyalkyltrialkyl ammonium alkyl sulfate salt in which the alkylradicals contain from 1 to 4 carbon atoms; and (2) about a molar equivalent thereof of a water-soluble salt from the group consisting of alkyl carboxylates and alkyl sulfates, the alkyl group of which contains from 8 to 20 carbon atoms.

2. The method of claim 1 in which the ratio of the application bath to the textile is between '10 to 50 parts of the former for each part by weight of textile.

3. The method of claim 1 in which the temperature of the bath is maintained at from F. to its boiling point.

4. The method of treating textile material which comprises imparting anti-static properties thereto by immersing the textile material in an aqueous solution containing about 0.5% by weight, based on the textile material, of a poly-beta methacrylyloxyethyldiethylmethyl ammonium methylsulfate, maintaining the temperature of the bath at about to F., adding about 100 parts of an aqueous solution containing about 0.5% by Weight, based on the textile material, of a sodium hexadecenyl sulfate and 1.5% by Weight, based on the textile material, of an isooctylphenol condensate with about 12 mols of ethylene oxide over a period of about one half hour, and thereafter drying the said textile material.

5. The method of treating textile material which comprises imparting anti-static properties thereto by treating the textile material first with an aqueous pad bath containing 15% by weight, based on the bath, of dimethylolurea containing about 20 parts monomer and 4 parts low polymer and about 0.5% by weight of ammonium phosphate catalyst, drying the textile material thoroughly, and then immersing it in an aqueous solution containing (1) from 0.01% to 0.1% by weight of a polyacrylyloxyalkyltrialkyl ammonium alkyl sulfate salt in which the alkyl radicals contain from 1 to 4 carbon atoms; and (2) about a molar equivalent thereof of a water-soluble salt from the group consisting of alkyl carboxylates and alkyl sulfates, the alkyl group of which contains from 8 to 20 carbon atoms, and thereafter drying the said textile material.

References Cited in the file of this patent UNITED STATES PATENTS 2,088,227 Battye et a1. 'July 27, 1937 2,138,763 Graves Nov. 29, 1938 2,393,863 Myers Jan. 29, 1947 2,461,043 Eisen Feb. 8, 1949 2,595,225 Cofiman May 6, 1952 2,677,699 Barney May 4, 1954 

5. THE METHOD OF TREATING TEXTILE MATERIAL WHICH COMPRISES IMPARTING ANTI-STATIC PROPERTIES THERETO BY TREATING THE TEXTILE MATERIAL FIRST WITH AN AQUEOUS PAD BATH CONTAINING 15% BY WEIGHT, BASED ON THE BATH, OF DIMETHYLOLUREA CONTAINING ABOUT 20 PARTS MONOMER AND 4 PARTS LOW POLYMER AND ABOUT 0.5% BY WEIGHT OF AMMONIUM PHOSPHATE CATALYST, DRYING THE TEXTILE MATERIAL THROUGHLY, AND THEN IMMERSING IT IN AN AQUEOUS SOLUTION CONTAINING (1) FROM 0.01% TO 0.1% BY WEIGHT OF A POLYACRYLYLOXYALKYLTRIALKYL AMMONIUM ALKYL SULFATE SALT IN WHICH THE ALKYL RADICALS CONTAIN FROM 1 TO 4 CARBON ATOMS; AND (2) ABOUT A MOLAR EQUIVALENT THEREOF OF A WATER-SOLUBEL SALT FROM THE GROUP CONSISTING OF ALKYL CARBOXYLATES AND ALKYL SULFATES, THE ALKYL GROUP OF WHICH CONTAINS FROM 8 TO 20 CARBON ATOMS, AND THEREAFTER DRYING THE SAID TEXTILE MATERIAL. 